Medical device

ABSTRACT

A soft tissue implant comprises a condensed surgical mesh having a plurality of monofilament biocompatible fibres  12 . Condensing of the fibres reduces the void space between adjacent fibres  12  in the mesh and reduces the surface area of the fibres  12  available for contact with tissue  18 . Condensation of the fibres  12  may be achieved by applying mechanical pressure, and/or vacuum, and/or heat to the mesh.

FIELD OF THE INVENTION

This invention relates generally to medical devices and morespecifically to soft tissue implants that can be used to repair injuredor otherwise defective tissue within the body (e.g., pelvic floorprolapse and hernias).

BACKGROUND

Stress urinary incontinence (SUI), pelvic floor prolapse, and herniasare serious health concerns worldwide. Millions of people suffer fromthese problems, and surgical procedures involving the placement ofimplants to stabilize or support the affected tissue are required.

Devices for treating tissue defects can be constructed from syntheticmaterials such as polypropylene, polytetrafluoroethylene, polyester, andsilicone. Devices constructed from non-synthetic materials can includeallografts, homografts, heterografts, xenografts, autologous tissues,cadaveric fascia, and fascia lata. The supply of non-synthetic devicescan vary greatly and certain sizes of non-synthetic materials can bedifficult to obtain. For example, autologous material may be difficultor impossible to harvest from some patients due to the health of thepatient or the size of the tissue needed for a repair.

Biomaterials, which work either by mechanical closure or by inducingstrong scar tissue, can also be used. However, the synthetic materialcan increase the rate of local wound complications such as seromas (byabout 30-50%), paraesthesia (by about 10-20%), and restriction ofmobility (by about 25%) (see Klinge et al., Eur. J. Surg. 164:951-960,1998). More specifically, biomaterial implants are used to support theabdominal wall, which has an average displacement elasticity of 25% at amaximum tensile strength of 16 N/cm (see Junge et al., Hernia 5:113-118,2001). Biomaterials with initially low bending stiffness may turn intohard sheets in the post implant period and fail to exhibit 25% strainunder forces of 16 N/cm. With excessive scar tissue formation, there isa decrease in abdominal wall mobility. Histological analysis ofexplanted biomaterials has revealed persistent inflammation at theinterface, even after several years of implantation, which is influencedby the weight of the biomaterial and the surface area in contact withthe recipient tissue. The persistent foreign body reaction isindependent of the inflammation time, but considerably affected by thetype of biomaterial (see Welty et al., Hernia 5:142-147, 2001; andKlinge et al., Eur. J. Surg. 165:665-673, 1999). Consequently, thepersistence of a foreign body reaction at the biomaterial-tissueinterface might cause severe problems, particularly in young patients,in whom the biomaterial is expected to hold for prolonged periods oftime.

Bard Mesh™ is a non-absorbable implant that is made from monofilamentpolypropylene fibres using a knitting process (C. R. Bard, Inc.,Cranston, R. I.; see also U.S. Pat. No. 3,054,406; U.S. Pat. No.3,124,136; and Chu et al., J. Bio. Mat. Res. 19:903-916, 1985). Thethickness for Bard Mesh™ and other commercially available implants isprovided in the table below. As indicated, the thinnest of thesematerials has a thickness of 0.016 inches. Thickness Material CompanyCode No. (inches) Bard Mesh C. R. Bard/Davol 112660 0.026 Prolene MeshJ&J/Ethicon PML 0.020 Prolene Soft Mesh J&J/Ethicon SPMXXL 0.016Gore-Tex Soft W. L. Gore 1315020020 0.079 Tissue Patch ProLite AtriumMedical 1001212-00 0.019 ProLite Ultra Atrium Medical 30721 0.016

Additional non-absorbable meshes are known (see U.S. Pat. Nos.2,671,444; 4,347,847; 4,452,245; 5,292,328; 5,569,273; 6,042,593;6,090,116; 6,287,316 (this patent describes the mesh marketed asProlene™; and U.S. Pat. No. 6,408,656). These products are all madeusing synthetic fibre technology. Different knit patterns impart uniquemechanical properties to each configuration.

A variety of absorbable or partially absorbable materials have beendescribed (see U.S. Pat. Nos. 4,633,873; 4,693,720; 4,838,884; and6,319,264). There are also a variety of implants used to treat urinaryincontinence in women (see U.S. Pat. Nos. 4,857,041; 5,840,011;6,042,534; 6,110,101; 6,306,079; and 6,355,065; see also U.S. Pat. Nos.5,112,344; 5,611,515; 5,637,074; 5,842,478; 5,860,425; 5,899,909;6,039,686; 6,273,852; 6,406,423; 6,478,727; 6,702,827; WO 2004/017862;WO 02/39890; and WO 02/26108).

At present, monofilament polypropylene surgical meshes are the mostwidely used soft tissue implants. Although serious complicationsassociated with implants are infrequent, they are well documented.Moreover, each of the implants presently in use are believed to have oneor more deficiencies. For example, their construction can result incharacteristics (e.g., wall thickness and surface area) that increasethe risk of an inflammatory response or of infection; seromas can formpostoperatively within the space between the prosthesis and the hosttissues; due to material content, width, and wall thickness, surgeonsmust make large incisions for implantation (the present implants can bedifficult to deploy in less invasive surgical methods); rough andirregular implant surfaces can irritate tissues and lead to the erosionof adjacent tissue structures; adhesions to the bowel can form when theimplant comes in direct contact with the intestinal tract; where poresize is reduced, there can be inadequate tissue ingrowth andincorporation; and the pore size and configuration of the implants doesnot permit adequate visualization through the implant duringlaparoscopic procedures. Additional complications include pain,discomfort, obstruction, and organ perforations.

SUMMARY

The present invention features medical devices that includebiocompatible material for stabilising or supporting a tissue of apatient's body. Methods for making the devices are also within the scopeof the invention. More specifically, the devices include condensedsurgical meshes with reduced void and surface contact areas (e.g., acondensed monofilament surgical mesh) produced from a biocompatiblepolymer without added materials (e.g. coatings). The studies conductedwith the condensed mesh indicate that, by reducing the void spacetherein (e.g., the space between fibres within the mesh), the mesh isless likely to cause inflammation. With a reduced surface area, thereare fewer places for inflammatory cells to aggregate. Void areareduction may create a superior device in other ways as well.

The term “implant” may be used instead of “device.” Soft tissue implantsare those suitable for application to any soft tissue within a patient'sbody, and they may also be referred to as surgical implants. While thepatient may be a human, the invention is not so limited; the implantscan be used to repair or stabilize soft tissue in any animal.

The methods of the invention include methods of making a soft tissueimplant by providing a surgical mesh and condensing the surgical mesh togenerate material useful as a soft tissue implant. If desired, one canfurther alter the size or shape of the material (e.g., one can trim theimplant or fold or roll it into a conical or tubular shape). As withother medical devices, the implants may be sterilized before use.

The surgical mesh can be obtained from a commercial supplier or madeusing methods known in the art. For example, a mesh can be made byextruding a biocompatible polymer or copolymer into a fibre and knittingor weaving the fibres together. To facilitate production, the processcan be mechanized. For example, the knitted mesh of the invention can bemade on any two-bar warp loom.

Useful polymers and copolymers are described as biocompatible as theyare non-toxic or sufficiently harmless to allow their use in humanpatients. The polymers and copolymers can be non-absorbable (e.g., theymay made with polypropylene, polyethylene, polyethylene terephthalate,polytetrafluoroethylene, polyaryletherketone, nylon, fluorinatedethylene propylene, polybutester, or silicone) or absorbable(polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone,polydioxanone or polyhydroxyalkanoate, or a copolymer thereof.Absorbable implants degrade following implantation, and the rate ofdegradation can vary greatly depending upon the amount and type ofmaterial used. In other embodiments, the polymer or copolymer caninclude a naturally occurring biological molecule, or a variant thereof,such as collagen. The fibres can be intertwined in many different waysby knitting or weaving. The spaces within the mesh may be referred to ascells or pores, and a given mesh can include uniformly or non-uniformlypatterned cells having any number of shapes (e.g., the cells or porescan be substantially round, square, oval-shaped or diamond-shaped). Thesize of the pores can also vary and may be uniform or non-uniform. Forexample, the mesh can include pores that are about 50 μm in diameter.

The mesh can be condensed in any way that reduces the void space betweenthe fibres. For example, one can apply mechanical pressure, vacuum,and/or heat to the mesh. The fibres are thermally set to a desired shapethat reduces the void space between and around the fibres of thesurgical mesh. The condensation force is applied for a time and underconditions sufficient to reduce the void space within the mesh or thearea of the implant available to contact a patient's tissue. We mayrefer to that area as the surface contact area.

The fibres most useful for creating the implant are monofilament fibres.Monofilament fibres are less prone to infection and inflammation.Consequently, a surgical mesh constructed from monofilament fibres is apreferred structure compared to multifilament based surgical meshes.Monofilament fibres have a consistent cross sectional area compared tomultifilament fibres that have small individual fibres bundled together.Multifilament fibres have an increased surface contact area compared tomonofilament fibres of the same diameter. In addition, monofilamentfibres are more stable when subjected to condensation treatment and areless likely to move in relation to adjacent fibres which preserves thecondensed structure.

The compressive force can be applied to the mesh uniformly, in whichcase the void space will be reduced in a substantially uniform waywithin the entire mesh. Alternatively, the force (e.g., pressure) can beapplied to the mesh non-uniformly. In that event, the extent to whichthe void space is reduced will vary from one region of the mesh toanother (the reduction being greater where the force is greater). Tofacilitate condensation, the force can be applied to the mesh while themesh is under vacuum.

Either before or after condensation, the mesh can be altered. Forexample, the mesh can be cut or otherwise fashioned into a differentshape before condensation. The shape change can include inserting, intothe mesh or material condensed therefrom, an opening for receiving anattachment element (e.g., a suture, staple, or other fixation device).The force may be applied to the mesh in such a way that a region forreceiving an attachment element (e.g., a point along the edge, or afolded edge, of the mesh or material) varies in density from a regionthat is not intended to receive an attachment element.

Depending upon the strength of the condensation, the thickness (oraverage thickness) of the material can vary. For example, the materialcan be about 0.001-0.040 inches thick. The overall dimensions of themesh or material can be unique or can be those of any presentlyavailable surgical mesh or implant. For example, the condensed materialsdescribed herein can be fashioned to support tissue (e.g., a part of thebladder, urethra, pelvic floor, or abdominal wall) and may have theoverall shape of any device presently used to do so.

The invention also features devices (e.g., soft tissue implants) made byany of the methods described herein. These devices are described furtherbelow and illustrated in the drawings.

In specific embodiments, the methods of the invention include providinga surgical mesh; placing the surgical mesh under vacuum; heating thesurgical mesh; compressing the surgical mesh by applying pressure to themesh (for a time and under conditions sufficient to reduce the voidspace within the mesh or the surface contact area); and cleaning and/orsterilizing the mesh, thereby generating material useful as a softtissue implant. The heating process can impact longitudinal elasticity;applying heat while applying tension to the implant can reduceelasticity).

In specific embodiments, the invention features a soft tissue implantcomprising a woven or knit monofilament mesh having a density greaterthan 0.081 g/cm³, the space between the monofilament mesh constitutingpores of about 500 μm to about 10 mm in diameter.

The implants of the present invention offer a combination of highporosity, high strength, and low material content, and they may have oneor more of the following advantages. They can include pores or porousstructures that stimulate fibrosis and reduce inflammation; they canreduce the risk of erosion and formation of adhesions with adjacenttissue (this is especially true with implants having a smooth surfaceand reduced surface contact area) and atraumatic (e.g., smooth, tapered,or rounded edges); they can simulate the physical properties (e.g.elasticity) of the tissue being repaired or replaced, which is expectedto promote more complete healing and minimise patient discomfort; theirsurface areas can be reduced relative to prior art devices (having areduced amount of material in contact with tissue may decrease thelikelihood of an immune or inflammatory response). Practically, thetechniques that can be used to produce the implants of the presentinvention are efficient and reproducible. The implants described hereinshould provide enhanced biocompatibility in a low profile configurationwhile maintaining the requisite strength for the intended purpose. Theimplants may also have improved wrinkle recovery memory.

According to the invention there is provided a soft tissue implantcomprising a condensed surgical mesh, the mesh comprising one or morebiocompatible fibres, at least one of the fibres comprising amonofilament fibre.

In one embodiment of the invention each fibre in the mesh comprises amonofilament fibre. The mesh may be knit from one or more fibres. Themesh may be woven from one or more fibres.

In one embodiment along at least part of at least one fibre, the fibreis condensed. The mesh may have a void space between adjacent fibres inthe mesh, and along the condensed part of the fibre, the mesh void spaceis reduced. The distance between adjacent fibres in the mesh may be inthe range of from approximately 5 μm to approximately 500 μm. Along thecondensed part of the fibre:${\frac{A_{v}}{A_{F}}\quad{may}\quad{be}} \leq 1.5$where:

-   -   A_(v)=area of the void between adjacent fibres in the mesh        available for tissue infiltration.

A_(F)=cross-sectional area of the fibre.

In one case $\frac{A_{v}}{A_{F}} \leq 1.0$$\frac{A_{v}}{A_{F}}\quad\text{may~~be~~approximately~~equal~~to~~0.6.}$

Along the condensed part of the fibre, the surface area of the fibreavailable for contact with tissue may be reduced. Along the condensedpart of the fibre: ${\frac{P_{FC}}{P_{F}}\quad\text{may~~be}} \leq 0.8$where:

-   -   P_(FC)=Perimeter of the fibre, at a cross-section of the fibre,        which is available for contact with tissue.    -   P_(F)=Total perimeter of the fibre, at a cross-section of the        fibre.

In one case $\frac{P_{FC}}{P_{F}} \leq 0.65$$\frac{P_{FC}}{P_{F}}\quad\text{may~~be~~approximately~~equal~~to~~0.5}$

In another embodiment the fibres are condensed at at least some pointsof intersection between the fibres. The fibres may be at least partiallyflattened at at least some points of intersection between the fibres. Atleast some of the points of intersection may be stitch loopintersections.

In one case the mesh has at least one overlap region, at which at leastone fibre overlaps at least one other fibre, at least one of the fibresbeing condensed at the overlap region. At the overlap region, thesurface of the mesh available for contact with tissue may be less thanthe sum of the total surface areas of the overlapping fibres. The ratioof the tissue contact area of the mesh to the sum of the total surfaceareas of the overlapping fibres may be less than or equal to 0.8. At theoverlap region, one fibre may be fused with an overlapping fibre. At theoverlap region, one fibre may engage with an overlapping fibre. Theengagement of one fibre with an overlapping fibre may substantiallyprevent in-growth of tissue between the overlapping fibres. Theoverlapping fibres may be condensed together.

In another embodiment the fibre comprises a polymer and/or a copolymer.The polymer and/or copolymer may be absorbable. The polymer and/orcopolymer may be non-absorbable.

The fibre may comprise polypropylene.

In another case the mesh is condensed substantially uniformly. The meshmay comprise a condensed region and an uncondensed region. The mesh maycomprise at least two regions which are differentially condensed.

In one embodiment the implant is configured for attachment to tissue.The mesh may comprise one or more attachment points. The mesh may bereinforced in the region of the attachment point. The implant may beconfigured to facilitate coupling of an attachment element to the mesh.In one case the attachment point comprises an attachment opening in themesh to receive an attachment element, such as a suture, and/or astaple, and/or an adhesive. The mesh may comprise one or more engagementformations for attachment of the mesh to tissue. The engagementformation may comprise a protrusion. The mesh may comprise a pluralityof protrusions configured in a wave-like or dimple like pattern.

In one embodiment at least part of the mesh is treated to increase thecoefficient of friction of the mesh. At least part of the mesh may havean increased surface roughness.

In another embodiment the mesh is configured to maintain the position ofthe mesh relative to tissue. The mesh may comprise one or moreengagement formations for engaging tissue.

At least a portion of the mesh may be of a composite configuration. Theimplant may comprise an inelastic element to reinforce the mesh. Theinelastic element may comprise one or more fibres. The inelastic elementmay be woven into the mesh. The inelastic element may be attached to asurface of the mesh.

In another case the thickness of at least part of the mesh is in therange of from 0.001 inches to 0.04 inches. The thickness of the mesh maybe substantially constant across the mesh. The thickness of the mesh mayvary across the mesh. The density of at least part of the mesh may begreater than 0.081 g/cm³. The density of the mesh may be substantiallyconstant across the mesh. The density of the mesh may vary across themesh.

In another embodiment the mesh pore size is uniform across the mesh. Themesh pore size may vary across the mesh.

The implant may comprise a three dimensional structure. The threedimensional structure may comprise a conical shape. The threedimensional structure may comprise a cylindrical shape.

In one embodiment at least some of the mechanical properties of the meshare substantially omnidirectional. The elasticity of the mesh may besubstantially omnidirectional.

In another aspect of the invention there is provided a method of forminga surgical mesh, comprising one or more biocompatible fibres, at leastone of the fibres comprising a monofilament fibre, the method comprisingthe step of condensing at least part of the mesh.

In one embodiment the method comprises the steps of:—

-   -   providing the one or more biocompatible fibres; and    -   forming the surgical mesh from the one or more fibres.

Each fibre in the mesh may comprise a monofilament fibre.

In one case the mesh is condensed by applying heat to at least part ofthe mesh. The mesh may be condensed by applying pressure to at leastpart of the mesh. The mesh may be condensed by applying a vacuum to atleast part of the mesh.

In one case the method comprises the step of heat-setting the mesh. Thestep of heat-setting may be performed before the step of condensing. Thestep of heat-setting may be performed after the step of condensing. Thestep of heat-setting may be performed during the step of condensing.

In another embodiment the method comprises the step of controlling thetexture of the mesh. The method may comprise the step of controlling thetexture of the external surface of the mesh. The texture may becontrolled by arranging the mesh in contact with a control surfacebefore the step of condensing is performed. The method may comprise thestep of maintaining the temperature of the control surface substantiallystable. The method may comprise the step of maintaining the pressure ofthe control surface substantially stable.

In one case the method comprises the step of forming the mesh into athree-dimensional structure. The method may comprise the step oftreating the mesh to make at least some of the mechanical properties ofthe mesh substantially omnidirectional. The mesh may be stretched in afirst direction while holding the mesh in a second directionperpendicular to the first direction.

In one case the mesh is formed by knitting the one or more fibres, orweaving the one or more fibres.

In another aspect the invention provides a method of making a softtissue implant, the method comprising:

-   -   (a) providing a surgical mesh; and    -   (b) condensing the surgical mesh to generate material useful as        a soft tissue implant

The method may comprise altering the size or shape of the material togenerate the soft tissue implant. Providing the surgical mesh maycomprise extruding a biocompatible polymer or copolymer into a fibre andforming the surgical mesh from the fibre. In one case the biocompatiblepolymer or copolymer is a non-absorbable polymer or copolymer. Thenon-absorbable polymer may be a polymer of polypropylene, polyethylene,polyethylene terephthalate, polytetrafluoroethylene,polyaryletherketone, nylon, fluorinated ethylene propylene,polybutester, or silicone, or a copolymer thereof. In another case thebiocompatible polymer or copolymer is an absorbable polymer. Theabsorbable polymer may be a polymer of polyglycolic acid (PGA),polylactic acid (PLA), polycaprolactone, polydioxanone orpolyhydroxyalkanoate, or a copolymer thereof. The biocompatible polymermay be collagen or a copolymer comprising collagen.

In one embodiment forming the surgical mesh comprises knitting thefibre. The mesh may comprise pores of a substantially uniform size. Themesh may comprise pores that are greater than 50 micrometers indiameter.

In one case condensing the surgical mesh comprises applying pressureand, optionally, heat to the mesh. The pressure or heat may be appliedfor a time and under conditions sufficient to reduce the void spacewithin the mesh. The pressure or heat may be applied for a time andunder conditions sufficient to reduce the surface area available forcontact with a patient's tissue. The pressure or heat may be applied tothe mesh uniformly. The pressure or heat may be applied to the meshnon-uniformly. The pressure or heat may be applied to the mesh while themesh is under vacuum.

In one case the method comprises inserting, into the material, anopening for receiving an attachment element. The material may be about0.001-0.040 inches thick. The material may be of a size and shapeappropriate for stabilizing or supporting the bladder neck, urethra,pelvic floor, or abdominal wall.

In one embodiment the method comprises fashioning the material into atubular or conical shape.

The invention also provides a soft tissue implant made by the method ofthe invention.

In a further aspect the invention provides a method of making a softtissue implant, the method comprising:

-   -   (a) providing a surgical mesh;    -   (b) condensing the surgical mesh by applying pressure and,        optionally, heat to the mesh, wherein the pressure and,        optionally, the heat, is applied for a time and under conditions        sufficient to reduce the void space within the mesh; and    -   (c) cleaning or sterilizing the mesh, thereby generating        material useful as a soft tissue implant.

The invention provides in a further aspect a soft tissue implantcomprising a woven or knit monofilament mesh having a density greaterthan 0.081 g/cm³, the space between the monofilament mesh constitutingpores of about 500 μm to about 10 mm in diameter.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart illustrating some of the steps in a method forproducing an implant for treating tissue defects;

FIGS. 2A and 2B are cross sectional diagrams of an uncondensed surgicalmesh implant;

FIG. 2A depicts the round and oval perimeters of monofilament fibres andthe fibre cross sections;

FIG. 2B depicts the perimeters and illustrates the area of the meshavailable to contact tissue once implanted into a patient also referredto as the area of void for tissue infiltration;

FIGS. 3A and 3B are cross sectional diagrams of the surgical meshimplant of FIGS. 2A and 2B following condensation;

FIG. 3A depicts the altered perimeters and FIG. 3B illustrates thereduced area of the mesh available for tissue contact;

FIGS. 4A-4C are scanning electron micrographs of a surgical mesh before(FIG. 4A) and after (FIG. 4B) condensation and with an attachednon-elastic element (FIG. 4C). The implant shown in FIG. 4C may bereferred to as a composite implant sling;

FIGS. 5A and 5B are scanning electron micrographs of Prolene™ Soft Mesh(no condensation) 35× and Mersilene™ Mesh (no condensation) 35×,respectively;

FIGS. 6A-6C are scanning electron micrographs of a polypropylene meshmade as described in Example 3, with no condensation, at 35×, 80×, and70×, respectively. FIG. 6D is a light micrograph of a polypropylene meshmade as described in Example 3, with no condensation, cross sectionshown at 125×.;

FIGS. 7A-7C are scanning electron micrographs of a polypropylene meshmade as described in Example 4, with condensation at a force of 10N/cm², heat application, and vacuum, at 35×, 80×, and 70×, respectively.FIG. 7D is a light micrograph of a polypropylene mesh made as describedin Example 4, with condensation at a force of 10 N/cm², heatapplication, and vacuum, cross section shown at 125×.;

FIGS. 8A-8C are scanning electron micrographs of a polypropylene meshmade as described in Example 5, with condensation at a force of 25N/cm², heat application, and vacuum, at 35×, 80×, and 70×, respectively.FIG. 8D is a light micrograph of a polypropylene mesh made as describedin Example 5, with condensation at a force of 25 N/cm², heatapplication, and vacuum, cross section shown at 125×.;

FIGS. 9A-9C are scanning electron micrographs of a polypropylene meshmade as described in Example 6, with condensation at a force of 50N/cm², heat application, and vacuum, at 35×, 80×, and 70×, respectively.FIG. 9D is a light micrograph of a polypropylene mesh made as describedin Example 6, with condensation at a force of 50 N/cm², heatapplication, and vacuum, cross section shown at 125×.;

FIGS. 10A-10C are scanning electron micrographs of a polypropylene meshmade as described in Example 7, with condensation at a force of 75N/cm², heat application, and vacuum, at 35×, 80×, and 70×, respectively.FIG. 10D is a light micrograph of a polypropylene mesh made as describedin Example 7, with condensation at a force of 75 N/cm², heatapplication, and vacuum, cross section shown at 125×.;

FIGS. 1A-11C are scanning electron micrographs of a polypropylene meshmade as described in Example 8, with condensation at a force of 100N/cm², heat application, and vacuum, at 35×, 80×, and 70×, respectively.FIG. 11D is a light micrograph of a polypropylene mesh made as describedin Example 4, with condensation at a force of 100 N/cm², heatapplication, and vacuum, cross section shown at 125×.;

FIGS. 12A-12C are scanning electron micrographs of a polypropylene meshmade as described in Example 9, with condensation at a force of 125N/cm² heat application, and vacuum, at 35×, 80×, and 70×, respectively.FIG. 12D is a light micrograph of a polypropylene mesh made as describedin Example 9, with condensation at a force of 125 N/cm², heatapplication, and vacuum, cross section shown at 125×.;

FIGS. 13A-13C are scanning electron micrographs of a polypropylene meshmade as described in Example 10, with condensation at a force of 250N/cm², heat application, and vacuum, at 35×, 80×, and 70×, respectively.FIG. 13D is a light micrograph of a polypropylene mesh made as describedin Example 10, with condensation at a force of 250 N/cm², heatapplication, and vacuum, cross section shown at 125×.;

FIGS. 14A-14D are light micrographs of hemotoxylin and eosin (H&E)stained 6 mil polypropylene meshes in cross section;

FIGS. 14A and 14C show a non-condensed mesh after implantation for 28days at 100× and 200×, respectively;

FIGS. 14B and 14D show a mesh condensed at a force of 75 N/cm², heatapplication, and vacuum, after implantation for 28 days at 100× and200×, respectively;

FIGS. 15A-15D are light micrographs of trichrome stained 6 milpolypropylene meshes in cross section;

FIGS. 15A and 15C show a non-condensed mesh after implantation for 28days at 100× and 200×, respectively; and

FIGS. 15B and 15D show a mesh condensed at a force of 75 N/cm², heatapplication, and vacuum, after implantation for 28 days at 100× and200×, respectively.

DETAILED DESCRIPTION

Referring to the figures, FIG. 1 illustrates one embodiment of thepresent methods. While the methods are described further below, they caninclude the steps of extruding and orienting a polymer into amonofilament fibre; converting the fibre into a surgical mesh; heatsetting the surgical mesh; condensing the surgical mesh to apredetermined density; reducing the thickness, void area, and surfacecontact area of the surgical mesh; forming the surgical mesh into athree-dimensional structure (a subassembly); converting the subassemblyinto a predetermined shape; cleaning the implant; and packaging andsterilizing the implant.

It will be appreciated that the method described with reference to FIG.1 is one method according to the invention. However other methods,including only some of the steps described with reference to FIG. 1,also fall within the scope of the invention is suit. It is not essentialthat all of the steps described with reference to FIG. 1 be included inthe method of the invention.

Referring to FIGS. 2A and 2B, schematics of an uncondensed surgical meshin cross section corresponding to the surgical mesh described in Example3 and shown in FIG. 6D, monofilament fibres 10 have substantially roundor oval perimeters and varying cross sectional area 12 depending uponthe plane of the section. Upon implantation, monofilament fibres 10 arein contact with surrounding tissue 14. Where monofilament fibres 10 arein direct contact, a portion of the perimeter 16 is unavailable tocontact surrounding tissue 14.

Referring to FIGS. 3A and 3B, schematics of a condensed surgical mesh incross section corresponding to the surgical mesh described in Example 6and shown in FIG. 10D, the perimeters of monofilament fibres 10 havebeen altered relative to those of the uncondensed mesh while the totalcross sectional area remains constant. Thus, the value of the perimeterin contact with tissue upon implantation and the void area 18 within theimplant available for tissue infiltration are both reduced in acondensed mesh relative to an uncondensed mesh.

Referring to FIG. 4A, a scanning electron micrograph of uncondensedpolypropylene surgical mesh, monofilament fibres 10 are used to knit amesh of large pore 20 construction that permits tissue ingrowth uponimplantation. Stitch loop intersections 22 are created during theknitting process. The surgical mesh is sold as Prolene™ Mesh (Ethicon,Somerville, N.J., USA). Referring to FIG. 4B, condensation zones 24 arecreated at stitch loop intersections 22 following the application ofvacuum, heat, and pressure, which compresses monofilament fibres 10 intoshapes having lower profiles. Nonelastic fibres 26 are applied to thesurgical mesh of FIG. 4C to generate a composite implant.

Referring to FIG. 5A, a scanning electron micrograph of uncondensedpolypropylene surgical mesh, monofilament fibres 10 are used to knit amesh of large pore 20 construction that permits tissue ingrowth uponimplantation. Stitch loop intersections 22 are created during theknitting process. The surgical mesh is sold as Prolene Soft™ Mesh(Ethicon, Somerville, N.J., USA). Referring to FIG. 5B, a scanningelectron micrograph of uncondensed polypropylene surgical mesh,multifilament fibres 28 are used to knit a mesh of large pore 20construction that permits tissue ingrowth upon implantation. Stitch loopintersections 22 are created during the knitting process. The surgicalmesh is sold as Mersilene™ Mesh (Ethicon, Somerville, N.J., USA).

Referring to FIGS. 6A and 6B, scanning electron micrographs ofuncondensed polypropylene mesh are shown at 35× and 80×, respectively.Monofilament fibres 10 are used to knit the mesh into a large pore 20construction which permits tissue ingrowth upon implantation. Stitchloop intersections 22 are created during the knitting process. Referringto FIG. 6C, a scanning electron micrograph of uncondensed polypropylenemesh, the surgical mesh thickness profile 30 is determined by thedistance between monofilament fibres 10 from a first side to a secondside of the surgical mesh (e.g., from the back to the front). Referringto FIG. 6D, a light micrograph of an uncondensed surgical mesh crosssection shown at 10×. The area of void for tissue infiltration 18 isidentified and the monofilament fibres 10 having substantially round oroval perimeters and varying cross-sectional area 12 depending on theplane of the section. Where monofilament fibres 10 are in directcontact, a portion of the perimeter 16 is unavailable to contactsurrounding tissue 14.

Referring to FIGS. 7A and 7B, scanning electron micrographs ofpolypropylene mesh condensed under vacuum, heat, and a force of 10N/cm², magnified 35× and 80×, respectively. Monofilament fibres 10 areused to knit the mesh into a large pore 20 construction which permitstissue ingrowth. Stitch loop intersections 22 are created during theknitting process. Condensation zones 24 are beginning to appear.Referring to FIG. 7C, a scanning electron micrograph of a cross sectionof a polypropylene mesh condensed under vacuum, heat, and a force of 10N/cm², magnified 70×. The surgical mesh thickness profile 30 isdetermined by the distance between monofilament fibres 10 at the frontand back of the condensed surgical mesh. Referring to FIG. 7D, a lightmicrograph of a surgical mesh cross section condensed under vacuum,heat, and a force of 10 N/cm² shown at 10×. The area of void for tissueinfiltration 18 is outlined and the monofilament fibres 10 havingsubstantially round or oval perimeters and varying cross-sectional area12 depending on the plane of the section. Where monofilament fibres 10are in direct contact, a portion of the perimeter 16 is unavailable tocontact surrounding tissue 14.

Referring to FIGS. 8A and 8B, scanning electron micrographs ofpolypropylene mesh condensed under vacuum, heat, and a force of 25N/cm², magnified 35× and 80×, respectively. Monofilament fibres 10 areused to knit the mesh into a large pore 20 construction which permitstissue ingrowth. Stitch loop intersections 22 are created during theknitting process. Condensation zones 24 are shown. Referring to FIG. 8C,a scanning electron micrograph of a cross section of a polypropylenemesh condensed under vacuum, heat, and a force of 25 N/cm², magnified70×. The surgical mesh thickness profile 30 is determined by thedistance between monofilament fibres 10 at the front and back of thecondensed surgical mesh. Referring to FIG. 8D, a light micrograph of asurgical mesh cross section Condensed under vacuum, heat, and a force of25 N/cm² shown at 10×. The area of void for tissue infiltration 18 isoutlined and the monofilament fibres 10 having substantially round oroval perimeters and varying cross-sectional area 12 depending on theplane of the section. Where monofilament fibres 10 are in directcontact, a portion of the perimeter 16 is unavailable to contactsurrounding tissue 14.

Referring to FIGS. 9A and 9B, scanning electron micrographs ofpolypropylene mesh condensed under vacuum, heat, and a force of 50N/cm², magnified 35× and 80×, respectively. Monofilament fibres 10 areused to knit the mesh into a large pore 20 construction which permitstissue ingrowth. Stitch loop intersections 22 are created during theknitting process. Condensation zones 24 are readily apparent. Referringto FIG. 9C, a scanning electron micrograph of a cross section of apolypropylene mesh condensed under vacuum, heat, and a force of 50N/cm², magnified 70×. The surgical mesh thickness profile 30 isdetermined by the distance between monofilament fibres 10 at the frontand back of the condensed surgical mesh. Referring to FIG. 9D, a lightmicrograph of a surgical mesh cross section condensed under vacuum,heat, and a force of 50 N/cm² shown at 10×. The area of void for tissueinfiltration 18 is outlined and the monofilament fibres 10 havingsubstantially round or oval perimeters and varying cross-sectional area12 depending on the plane of the section. Where monofilament fibres 10are in direct contact, a portion of the perimeter 16 is unavailable tocontact surrounding tissue 14.

Referring to FIGS. 10A and 10B, scanning electron micrographs ofpolypropylene mesh condensed under vacuum, heat, and a force of 75N/cm², magnified 35× and 80×, respectively. Monofilament fibres 10 areused to knit the mesh into a large pore 20 construction which permitstissue ingrowth. Stitch loop intersections 22 are created during theknitting process. Condensation zones 24 are readily visible. Referringto FIG. 10C, a scanning electron micrograph of a cross section of apolypropylene mesh condensed under vacuum, heat, and a force of 75N/cm², magnified 70×. The surgical mesh thickness profile 30 isdetermined by the distance between monofilament fibres 10 at the frontand back of the condensed surgical mesh. Referring to FIG. 10D, a lightmicrograph of a surgical mesh cross section condensed under vacuum,heat, and a force of 75 N/cm² shown at 10×. The area of void for tissueinfiltration 18 is outlined and the monofilament fibres 10 havingsubstantially round or oval perimeters and varying cross-sectional area12 depending on the plane of the section. Where monofilament fibres 10are in direct contact, a portion of the perimeter 16 is unavailable tocontact surrounding tissue 14.

Referring to FIGS. 1A and 1B, scanning electron micrographs ofpolypropylene mesh condensed under vacuum, heat, and a force of 100N/cm², magnified 35× and 80×, respectively. Monofilament fibres 10 areused to knit the mesh into a large pore 20 construction which permitstissue ingrowth. Stitch loop intersections 22 are created during theknitting process. Condensation zones 24 are readily visible. Referringto FIG. 11C, a scanning electron micrograph of a cross section of apolypropylene mesh condensed under vacuum, heat, and a force of 100N/cm², magnified 70×. The surgical mesh thickness profile 30 isdetermined by the distance between monofilament fibres 10 at the frontand back of the condensed surgical mesh. Referring to FIG. 11D, a lightmicrograph of a surgical mesh cross section condensed under vacuum,heat, and a force of 100 N/cm² shown at 10×. The area of void for tissueinfiltration 18 is outlined and the monofilament fibres 10 havingsubstantially round or oval perimeters and varying cross-sectional area12 depending on the plane of the section. Where monofilament fibres 10are in direct contact, a portion of the perimeter 16 is unavailable tocontact surrounding tissue 14.

Referring to FIGS. 12A and 12B, scanning electron micrographs ofpolypropylene mesh condensed under vacuum, heat, and a force of 125N/cm², magnified 35× and 80×, respectively. Monofilament fibres 10 areused to knit the mesh into a large pore 20 construction which permitstissue ingrowth. Stitch loop intersections 22 are created during theknitting process. Condensation zones 24 are readily visible. Referringto FIG. 12C, a scanning electron micrograph of a cross section of apolypropylene mesh condensed under vacuum, heat, and a force of 125N/cm², magnified 70×. The surgical mesh thickness profile 30 isdetermined by the distance between monofilament fibres 10 at the frontand back of the condensed surgical mesh. Referring to FIG. 12D, a lightmicrograph of a surgical mesh cross section condensed under vacuum,heat, and a force of 125 N/cm² shown at 10×. The area of void for tissueinfiltration 18 is outlined and the monofilament fibres 10 havingsubstantially round or oval perimeters and varying cross-sectional area12 depending on the plane of the section. Where monofilament fibres 10are in direct contact, a portion of the perimeter 16 is unavailable tocontact surrounding tissue 14.

Referring to FIGS. 13A and 13B, scanning electron micrographs ofpolypropylene mesh condensed under vacuum, heat, and a force of 250N/cm², magnified 35× and 80×, respectively. Monofilament fibres 10 areused to knit the mesh into a large pore 20 construction which permitstissue ingrowth. Stitch loop intersections 22 are created during theknitting process. Condensation zones 24 are readily visible. Referringto FIG. 13C, a scanning electron micrograph of a cross section of apolypropylene mesh condensed under vacuum, heat, and a force of 250N/cm², magnified 70×. The surgical mesh thickness profile 30 isdetermined by the distance between monofilament fibres 10 at the frontand back of the condensed surgical mesh. Referring to FIG. 12D, a lightmicrograph of a surgical mesh cross section condensed under vacuum,heat, and a force of 250 N/cm² shown at 10×. The area of void for tissueinfiltration 18 is outlined and the monofilament fibres 10 havingsubstantially round or oval perimeters and varying cross-sectional area12 depending on the plane of the section. Where monofilament fibres 10are in direct contact, a portion of the perimeter 16 is unavailable tocontact surrounding tissue 14.

Referring to FIGS. 14A and 14C, a light micrograph of an H&E stained 6mil uncondensed polypropylene mesh placed subcutaneously in tissue for28 days, at magnifications of 100× and 200×, respectively. Monofilamentfibres 10 and the cross sectional areas therein 12 are visible.Inflammatory cells 40 are present in surrounding tissue 14. Fewerinflammatory cells 40 are present around monofilament fibres 10 not indirect contact with tissue 16. Referring to FIGS. 14B and 14D, a lightmicrograph of an H&E stained 6 mil polypropylene mesh condensed undervacuum, heat, and a force of 75 N/cm² and placed subcutaneously intissue for 28 days, at magnifications of 100× and 200×, respectively.Monofilament fibres 10 and the cross sectional areas therein 12 arevisible. Inflammatory cells 40 are present in surrounding tissue 14.Fewer inflammatory cells 40 are present around monofilament fibres 10not in direct contact with tissue 16.

Referring to FIGS. 15A and 15C, a light micrograph of a trichromestained 6 mil uncondensed polypropylene mesh placed subcutaneously intissue for 28 days, at magnifications of 100× and 200×, respectively.Monofilament fibres 10 and the cross sectional areas therein 12 arevisible. Collagen/scar tissue formation 42 is present around theperimeter of monofilament fibres 10 in contact with tissue 14. Referringto FIGS. 15B and 15D, a light micrograph of a trichrome stained 6 milpolypropylene mesh condensed under vacuum, heat, and a force of 75 N/cm²and placed subcutaneously in tissue for 28 days, at magnifications of100× and 200×, respectively. Monofilament fibres 10 and the crosssectional areas therein 12 are visible. Collagen/scar tissue formation42 is present around the perimeter of the fibres in contact with tissue14. The thickness of the surgical mesh influences the amount ofcollagen/scar tissue formation 42 as the body responds to an implant byfilling voids. The density and organization of the collagen/scar tissueformation is higher for thinner implants with reduced surface area.

Preliminary studies suggest the implants described herein have betterproperties than many existing devices. Some of the parameters describedbelow are useful in characterizing the improvements.

Void Area Ratio=A_(V)/A_(f) where A_(f) is the area of the fibre crosssections and A_(V) is the area of void for tissue infiltration. Thisratio is particularly important at fibre intersections within thesurgical mesh fabric because A_(V) can increase in these regions when astitch loop intersection is created. Consequently, a reduced void areais present in the condensed surgical mesh, which can lead to reducedlevels of inflammation and scar tissue formation. The devices of theinvention can have a Void Area Ratio of 1.50 or lower, whethercalculated for the device as a whole or a portion thereof (e.g., atstitch loop intersections or in certain regions of the surgical mesh).

Surface Contact Ratio=P_(fc)/P_(f) where P_(fc) is the perimeter offibres in contact with tissue for a cross section of the surgical meshimplant and P_(f) is the perimeter of fibre for a cross section of thesurgical mesh implant. This ratio is particularly important at fibreintersections within the surgical mesh fabric because the amount offibre can increase in these regions when a stitch loop intersection iscreated. For uncondensed surgical meshes, the Surface Contact Ratio isestimated to approach 1.00 as the fibres are in direct contact only atisolated points and the majority of the fibres present are in contactwith tissue. Reduced surface contact between the fibre and tissue ispresent in the condensed surgical mesh, which can lead to reduced levelsof inflammation and scar tissue formation. The devices described hereincan have a Surface Contact Ratio of 0.80 or lower whether calculated forthe device as a whole or a portion thereof (e.g., at stitch loopintersections or in certain regions of the surgical mesh).

The geometry of the surface contact area of surgical mesh can also beimportant. The geometry of the condensation zone within condensedsurgical meshes is more uniform and distributes force to tissue moreevenly. The value for surface contact area under a controlled load canbe measured using pressure sensitive film. The surgical mesh is placedadjacent to a pressure sensitive film (e.g., a film containingmicrocapsules that change colour under certain loads). Film formeasuring such values is available under the trade name Prescale™(Fujifilm). The surface contact area of the condensed surgical meshunder a controlled load can be measured in this manner. Surface contactareas for surgical meshes of a known density can be compared atdifferent loads. Ideally, a light weight and low surface area surgicalmesh with a low area density would have an increase in surface contactarea with tissue under a given load to minimize irritation at isolatedpoints. Increased surface contact area in the outer portion of lowweight surgical meshes with improved void area ratios and surfacecontact ratios, may reduce inflammation, tissue reaction, and theerosion of the surgical mesh into adjacent tissue.

The material within the implants described herein can have uniform ornon-uniform properties. For example, one or more of the physicalattributes described above (e.g., the void area ratio or surface contactratio) can vary at one or more points within the implant or along theimplant's peripheral edge to improve suture or staple retentionstrength. For example, where the implant is a sheet of mesh, theperiphery (e.g., about ⅛ to about ⅞ inches around the perimeter of thedevice) can remain uncondensed or be condensed to a lesser extent thanthe mesh within the periphery. The strength of material along theperipheral edges (e.g., the tensile strength), or at other selectedpoints within the device, may be higher to improve the physicalproperties in this region so that sutures or other fixation devices donot pull out and cause failure. The material content in these regionscan also be increased relative to that of the starting mesh to improvethe physical properties of the device (e.g., additional material can beadded to reinforce one or more points within the device). In oneembodiment, attachment points such as reinforced areas or openings arecreated within the device (e.g., along the device's edge) for receivingsutures, staples, adhesives, and the like. The attachment points canalso be used to attach separate panels to one another to create thesurgical mesh implant. Accordingly, in specific embodiments, the devicescan include means to facilitate coupling of an attachment element to thedevice (e.g., an opening for receiving an attachment element). In someinstances, the device can further include all or part of an attachmentelement (e.g., a staple, suture, or adhesive) to facilitate attachmentof the device to body tissue of a patient. The adhesive can be anybiological glue or physiologically acceptable adhesive.

Alternatively, or in addition, the implant can include areas that havebeen adapted to increase the coefficient of friction and thereby inhibitthe implant's movement in the tissue. Supporting materials, which may beincluded to facilitate attachment to a fastener or to generallyreinforce the implant, can be shape memory materials (e.g., shape memoryalloys such as Nitinol™). More generally, any of the implants caninclude a shape memory material such as Nitinol™ to facilitate sizing,attachment, and implantation.

The means to maintain the device in position relative to a patient'stissue (i.e., an engagement means) can be employed after implantation ordeployment. Where the shape of the device alone is not sufficient tomaintain its position, the engagement means can be employed afterimplantation or deployment. The engagement means can include one or moreprotrusions (e.g., a plurality of protrusions arranged in a wave-like ordimple-like pattern). Undulating elements may be in phase, withforce-displacement characteristics suitable for placement and support.

The overall shape of the implants can vary tremendously and will beselected for use depending upon the size of the individual to be treatedand/or the tissue to be repaired. The overall length, width, and shapeof the implants can be varied and designed to support a certain area. Inone embodiment, the implant includes separate panels that are positionedindividually to support a tissue defect. Devices made by the methodsdescribed herein can be produced in various three-dimensional forms tofacilitate placement and sizing. Generally, the implant can beconfigured to conform to the shape of the tissue requiring repair. Forexample, an implant having a curvature can be used to construct asubstantially conical shape, and materials can be readily configured toextend circumferentially around a tissue. Essentially any substantiallytwo-dimensional soft tissue implant can be thermoformed into athree-dimensional shape after condensing the surgical mesh.

In one case, a portion of the biocompatible material is movable from adelivery configuration to a deployment configuration. Preferably thedelivery configuration is of a lower-profile than the deploymentconfiguration. The device comprises means to support the portion of thebiocompatible material in the deployment configuration.

Biocompatible materials useful in monofilament fibre 10 or multifilamentfibre 28 can include non-absorbable polymers such as polypropylene,polyethylene, polyethylene terephthalate, polytetrafluoroethylene,polyaryletherketone, nylon, fluorinated ethylene propylene,polybutester, and silicone, or copolymers thereof (e.g., a copolymer ofpolypropylene and polyethylene); absorbable polymers such aspolyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone,polydioxanone and polyhydroxyalkanoate, or copolymers thereof (e.g., acopolymer of PGA and PLA); or tissue based materials (e.g., collagen orother biological material or tissue obtained from the patient who is toreceive the implant or obtained from another person or source (e.g., ananimal source)). The polymers can be of the D-isoform, the L-isoform, ora mixture of both. An example of a biocompatible fibre 10 suitable forproducing the surgical mesh implant is polypropylene. Non-absorbablepolymers and copolymers are not substantially resorbed by the body overtime, whereas absorbable polymers degrade, to at least some appreciableextent, over time. Polymers and copolymers within commercially availablesurgical products, including currently available surgical meshes, aresuitable for use with the present implants.

One or more layers or pieces of absorbable and non-absorbable mesh canbe joined within the implant. For example, an implant can include anonabsorbable material and an absorbable material of the same size andshape as the nonabsorbable material or a portion thereof. The absorbablematerial can be configured to reduce the elasticity of the implant andcan be thermally attached to the nonabsorbable material.

In some embodiments, biocompatible material within the implant is shapedto distribute the stabilizing and/or supporting force exerted againsttissue. The biocompatible material may comprise a surface thatdistributes forces against the tissue evenly.

Given the woven or knitted configuration of the mesh, the devices canfacilitate tissue ingrowth and/or cellular infiltration and are porous.The pores within the devices can be arranged in regular or irregularpatterns. For example, a material can include a plurality of pores of afirst type (e.g., a first size and/or shape) arranged into a firstpattern and of a second type (e.g., a second size or shape) arrangedinto a second pattern. The size of the pores can vary, and can begreater than 50 μm. In specific embodiments, one or more of the pores inthe plurality has a diameter, measured along the longest axis of thepore, of about 10 to about 10,000 μm (e.g., about 10, 50, 100, 200, 500,1,000, 2,500, 5,000, 6,000, 7,000, 8,000, or 9,000 μm). The pores canvary in shape and, either before or after condensation, may beessentially round, oval, hexagonal or diamond-shaped. One or more of thepores of the plurality may be substantially the same shape as the poresshown in FIG. 6.

The biocompatible material can have a relatively high burst and tensilestrength and can have a relatively low co-efficient of friction. Inanother case, a portion of the base biocompatible material can have arelatively high co-efficient of friction. The devices may also comprisemeans to determine the magnitude and/or direction of a force (e.g., aforce applied to a portion of the biocompatible material when in contactwith a patient's tissue). Preferably, the device comprises means todetermine the magnitude and/or direction of a force applied to thematerial by visual inspection. In some embodiments, the geometricalconfiguration of at least part of the portion of the biocompatiblematerial can be altered in response to a change in the magnitude and/ordirection of a force applied. For example, a coloured filament can beincorporated into any of the materials to create a geometry, and one mayuse an instrument to measure the magnitude and/or direction of a forceapplied to the device. The soft tissue implant may comprise areas thatdistribute the force transmitted to the surrounding tissue more evenly.For example, at the fibre intersections, raised fibres can create roughareas that increase the force transmitted to tissue in select areas.Similarly, the implants can include regions that have reduced crosssectional areas, which can reduce inflammation and scar tissue build up.This is especially true at fibre intersections where raised fibres canincrease the cross sectional area.

The thickness of the implant can also vary and can be less than about0.040 inches. For example, a single porous layer of mesh within thedevice can be less than about 0.039 inches, 0.038 inches, 0.037 inches,0.036 inches, 0.035 inches, 0.034 inches, 0.033 inches, 0.032 inches,0.031 inches, 0.030 inches, 0.029 inches, 0.028 inches, 0.027 inches,0.026 inches, 0.025 inches, 0.024 inches, 0.023 inches, 0.022 inches,0.021 inches, 0.020 inches, 0.019 inches, 0.018 inches, 0.017 inches,0.016 inches, 0.015 inches, 0.014 inches, 0.013 inches, 0.012 inches,0.011 inches, 0.010 inches, 0.009 inches, 0.008 inches, 0.007 inches,0.006 inches, 0.005 inches, 0.004 inches, 0.003 inches, 0.002 inches, orabout 0.001 inch. However, a given implant can include more than onelayer of mesh or regions in which some portion of the mesh is coveredwith a second layer. For example, an implant can include a first porousbiocompatible surgical mesh and a second porous biocompatible surgicalmesh, the thickness of the implant being less than about 0.080 inches.

The implants can be produced by extruding a biocompatible polymer into afibre and forming a surgical mesh implant using a textile based process.As noted, the implants are designed to engage a tissue defect and caninclude a bioresorbable or biodegradable material that will stay inposition and support the tissue defect over a predetermined time. Theimplants can be produced by a number of different methods. In oneembodiments, the implants are produced by extruding a firstbiocompatible polymer to form a fibre; forming a surgical mesh fabricfrom the fibre; heat setting the surgical mesh fabric; applying anonelastic biocompatible material to the surgical mesh fabric;compressing the surgical mesh fabric to a predetermined density;reducing the thickness and roughness of the surgical mesh fabric;forming the surgical mesh fabric into a three-dimensional structure; andcutting the soft tissue implant into a predetermined shape. In thismethod or any other, the method may further include the steps ofcleaning and/or sterilizing the implant. Once formed, the implants canbe packaged for sale or distribution.

Other methods include: extruding a first biocompatible polymer to form afibre; forming a surgical mesh fabric from the fibre; compressing themesh fabric for a controlled period of time to a predetermined densityusing a combination of heat and pressure; heat setting the surgical meshfabric; reducing the thickness and roughness of the surgical meshfabric; forming the surgical mesh fabric into a three-dimensionalstructure; and cutting the soft tissue implant into a predeterminedshape.

Other methods include: extruding a first biocompatible polymer to form afibre; forming a surgical mesh fabric from the fibre; compressing themesh fabric for a controlled period of time to a predetermined densityusing a combination of heat and pressure with a vacuum source; heatsetting the surgical mesh fabric; compressing the surgical mesh fabricto a predetermined density; reducing the thickness and roughness of thesurgical mesh fabric; forming the surgical mesh fabric into athree-dimensional structure; and cutting the soft tissue implant into apredetermined shape.

Other methods include: extruding a first biocompatible polymer to form afibre; forming a surgical mesh fabric from the fibre; stretching thesurgical mesh fabric under a predetermined load; heat setting thesurgical mesh fabric; applying a nonelastic biocompatible material tothe surgical mesh fabric; compressing the surgical mesh fabric to apredetermined density; reducing the thickness and roughness of thesurgical mesh fabric; forming the surgical mesh fabric into athree-dimensional structure; and cutting the soft tissue implant into apredetermined shape.

Other methods include: extruding a first biocompatible polymer to form afibre; forming a surgical mesh fabric from the fibre; heat treating thesurgical mesh fabric in a manner that creates a mesh with varying poredimensions; applying a nonelastic biocompatible material to the surgicalmesh fabric; compressing the surgical mesh fabric to a predetermineddensity; reducing the thickness and roughness of the surgical meshfabric; forming the surgical mesh fabric into a three-dimensionalstructure; and cutting the soft tissue implant into a predeterminedshape.

Other methods include: extruding a first biocompatible polymer to form afibre; forming a surgical mesh fabric from the fibre; heat setting thesurgical mesh fabric; applying a nonelastic biocompatible material tothe surgical mesh fabric; selectively compressing the surgical meshfabric in certain regions to a predetermined density; reducing thethickness and roughness of the surgical mesh fabric; forming thesurgical mesh fabric into a three-dimensional structure; and cutting thesoft tissue implant into a predetermined shape.

Other methods include: extruding a first biocompatible polymer to form afibre; forming a surgical mesh fabric from the fibre; heat setting thesurgical mesh fabric; applying a nonelastic biocompatible material tothe surgical mesh fabric; selectively compressing the surgical meshfabric to varying degrees in certain regions to a predetermined density;reducing the thickness and roughness of the surgical mesh fabric;forming the surgical mesh fabric into a three-dimensional structure; andcutting the soft tissue implant into a predetermined shape.

A soft tissue implant can be created with a surface that has controlledtexture and geometry by subjecting the mesh fabric to the aboveprocesses while in contact with a textured surface and shaped geometryat temperatures and pressures that are sufficient to permanently alterthe surgical mesh implant characteristics.

Medical applications for the soft tissue implant technology describedherein include but are not limited to procedures for treating stressurinary incontinence, pelvic floor prolapse, and hernia repair. The softtissue implant can be produced or selected in a variety of shapes andsizes and from a variety of materials for a particular indication. Forexample, a surgeon may select a non-absorbable implant for patients thatrequire permanent treatment with an implant having long-term durabilityand strength. Alternatively, the surgeon may select an absorbable softtissue implant for patients that require temporary treatment and tissueremodelling. Generally, absorbable implants are chosen when possible toavoid the potential complications associated with a permanent implant.Consistent with the properties described herein, the surgeon can movethe devices from a delivery configuration to a deployment configuration,the delivery configuration being of a lower-profile than the deploymentconfiguration. Implants with a reduced profile can be produced andimplanted in a minimally invasive fashion; as they are pliable, they canbe placed or implanted through smaller surgical incisions. As thedevices are also porous, they are expected to have improved opticalproperties, allowing the surgeon to visualize underlying tissue throughthe implant.

EXAMPLES Example 1

We constructed an implant using polypropylene surgical mesh. A sectionof PML Prolene Mesh (Ethicon, Somerville, N.J., USA) was combined with a#2 SurgiPro™ polypropylene suture (Tyco Healthcare, North Haven, Conn.,USA) to create a composite implant. The suture material was wovenbetween the surgical mesh in 5 mm increments. The assembly was broughtunder vacuum to 160° C. under a force of 100 N/cm² between two layers ofApical 5 mil polyimide film using a Lauffer RLKV 40/1 vacuum laminationpress. The surgical mesh had a thickness of 0.0193 inches before thepressure and heat treatment and a thickness of 0.0093 inches after thetreatment. In addition, the composite assembly exhibited a lowerelasticity compared to the untreated (uncondensed) surgical mesh.

Example 2

A section of SPMXXL Prolene Mesh (Ethicon, Somerville, N.J., USA) wascombined with a #2 SurgiPro™ polypropylene suture (Tyco Healthcare,North Haven, Conn., USA) to create a composite implant. The suturematerial was woven between the surgical mesh in 5 mm increments. Theassembly was brought under vacuum to 160° C. under a force of 100 N/cm²between two layer of Apical 5 mil polyimide film using a Lauffer RLKV40/1 vacuum lamination press. The surgical mesh had a thickness of0.0159 inches before the pressure and heat treatment and a thickness of0.0090 inches after the treatment. In addition, the composite assemblyexhibited a lower elasticity compared to the original surgical mesh.

Example 3

We constructed a knitted polypropylene surgical mesh implant using 4 milmonofilament polypropylene fibre. The fibre was produced using MarlexHGX-030-01 polypropylene homopolymer. The knitted surgical mesh hadelasticity in the machine and transverse directions. A warp knit wasemployed to give the mesh exceptional tensile strength and to preventruns and unravelling. A suitable mesh is produced when employing thefollowing pattern wheel or chain drum arrangements: front guide bar,1-0/1-2/2-3/2-1 and back guide bar, 2-3/2-1/1-0/1-2. Examples 4-10 aresimilar. They differ in the amount of force applied to the mesh, from 10N/cm² to 250 N/cm², respectively.

Example 4

The surgical mesh implant disclosed in Example 3 was condensationtreated. The surgical mesh implant was brought to 155° C. under 10 N/cm²with vacuum between two layers of Kapton 2 mil polyimide film using aLauffer RLKV 40/1 vacuum lamination press.

Example 5

The surgical mesh implant disclosed in Example 3 was condensationtreated. The surgical mesh implant was brought to 155° C. under 25 N/cm²with vacuum between two layers of Kapton 2 mil polyimide film using aLauffer RLKV 40/1 vacuum lamination press.

Example 6

The surgical mesh implant disclosed in Example 3 was condensationtreated. The surgical mesh implant was brought to 155° C. under 50 N/cm²with vacuum between two layers of Kapton 2 mil polyimide film using aLauffer RLKV 40/1 vacuum lamination press.

Example 7

The surgical mesh implant disclosed in Example 3 was condensationtreated. The surgical mesh implant was brought to 155° C. under 75 N/cm²with vacuum between two layers of Kapton 2 mil polyimide film using aLauffer RLKV 40/1 vacuum lamination press.

Example 8

The surgical mesh implant disclosed in Example 3 was condensationtreated. The surgical mesh implant was brought to 155° C. under 100N/cm² with vacuum between two layers of Kapton 2 mil polyimide filmusing a Lauffer RLKV 40/1 vacuum lamination press.

Example 9

The surgical mesh implant disclosed in Example 3 was condensationtreated. The surgical mesh implant was brought to 155° C. under 125N/cm² with vacuum between two layers of Kapton 2 mil polyimide filmusing a Lauffer RLKV 40/1 vacuum lamination press.

Example 10

The surgical mesh implant disclosed in Example 3 was condensationtreated. The surgical mesh implant was brought to 155° C. under 250N/cm² with vacuum between two layers of Kapton 2 mil polyimide filmusing a Lauffer RLKV 40/1 vacuum lamination press.

The void area ratio of the materials described in Examples 3-10 wasmeasured according to method described previously. The void area ratiomeasures the ratio of the area of the fibre cross sections and the areaof void for tissue infiltration. This ratio was measured at fibreintersections within the surgical mesh fabric. A reduced void area ispresent in the condensed surgical mesh. It should be noted, however,that an increase in the force applied to the monofilament surgical meshcan cause damage to the fibres, which results in higher void arearatios. Void Area Ratio Product Force (N/cm²) Void Area Ratio Example 30 3.26 Example 4 10 1.74 Example 5 25 1.22 Example 6 50 0.68 Example 775 0.70 Example 8 100 0.56 Example 9 125 2.00 Example 10 250 1.71

The surface contact ratio of the materials described in Examples 3-10was measured according to the method described previously. The surfacecontact ratio measures the ratio of the perimeter of fibres in contactwith tissue to the perimeter of fibres for a cross section. This ratiowas measured at fibre intersections within the surgical mesh fabric. Areduced surface contact area is present in the condensed surgical mesh.Surface Contact Ratio Product Force (N/cm²) Surface Contact RatioExample 3 0 0.88 Example 4 10 0.91 Example 5 25 0.69 Example 6 50 0.70Example 7 75 0.52 Example 8 100 0.46 Example 9 125 0.62 Example 10 2500.76

The dimensions of the materials described in Examples 3-10, ProleneSoftm mesh, and Mersilene™ Mesh were measured according to ASTM D5947-03Standard Test Methods for Physical Dimensions of Solid PlasticsSpecimens. The thickness of the materials impacts the cross sectionalarea of the surgical mesh implants. In addition, the density of thematerial provides a measurement to determine the amount of material asit relates to cross sectional area. The density should correlate to theVoid Area Ratio described above for condensed surgical mesh implants.The thickness decreases and the density increases with an increase inthe condensation force applied per unit area. Thickness Product Force(N/cm²) Thickness (cm) Prolene Soft ™ Mesh 0 0.040 Mersilene ™ Mesh 00.024 Example 3 0 0.039 Example 4 10 0.026 Example 5 25 0.021 Example 650 0.019 Example 7 75 0.016 Example 8 100 0.015 Example 9 125 0.014Example 10 250 0.011 Density Product Force (N/cm²) Density (g/cm³)Prolene Soft ™ Mesh 0 0.081 Mersilene ™ Mesh 0 0.130 Example 3 0 0.086Example 4 10 0.097 Example 5 25 0.114 Example 6 50 0.123 Example 7 750.143 Example 8 100 0.171 Example 9 125 0.208 Example 10 250 0.237

The burst strength of the materials described in Examples 3-10, ProleneSoft™ mesh, and Mersilene™ Mesh was measured according to ASTM D3787-01Bursting Strength of Textiles (Constant Rate of Transverse). Testspecimens measuring 90.0 mm wide and 90.0 mm long were loaded into aZwick tensile test machine with a grip to grip separation of 1.0 mm anda test speed of 305 mm/min. Burst strength provides a measurement of theforce required to rupture the surgical mesh implants. In addition, theratio of density/thickness to burst strength provides a measurement ofsurgical mesh implant strength as it relates to the cross sectionalarea. The burst strength increased moderately with increase in thecondensation force applied per unit area up to 125 N/cm². The samplewith a condensation force of 250 N/cm² showed a decrease in burststrength. Burst Product Force (N/cm²) Burst (Fmax N) Prolene Soft ™ Mesh0 274 Mersilene ™ Mesh 0 129 Example 3 0 194 Example 4 10 222 Example 525 210 Example 6 50 225 Example 7 75 223 Example 8 100 209 Example 9 125227 Example 10 250 195 Density/Burst Ratio Density (g/cm³)/Burst ProductForce (N/cm²) (Fmax N) Prolene Soft Mesh 0 0.00030 Mersilene Mesh 00.00101 Example 3 0 0.00044 Example 4 10 0.00044 Example 5 25 0.00054Example 6 50 0.00055 Example 7 75 0.00064 Example 8 100 0.00082 Example9 125 0.00092 Example 10 250 0.00121

The suture retention of the materials described in Examples 3-10,Prolene Soft™ mesh, and Mersilene™ Mesh was measured according to ASTMD882-02 Standard Test Method for Tensile Properties of Thin PlasticSheeting. Test specimens measuring 25.4 mm wide by 75.0 mm long wereloaded into a Zwick tensile test machine with a grip to grip separationof 3.0 mm and a test speed of 500 mm/nin. Materials were tested in themachine and transverse directions. Suture retention provides ameasurement of the force required to disrupt the edge of the material.The suture retention strength was maintained with an increase in thecondensation force applied per unit area up to 75 N/cm². The sampleswith a condensation force of 100 and 125 N/cm² showed a moderatedecrease in suture retention strength and the samples with acondensation force of 250 N/cm² showed a more significant decrease.Suture Machine Suture Machine Product Force (N/cm²) (Fmax N) ProleneSoft ™ Mesh 0 24.8 Mersilene ™ Mesh 0 10.0 Example 3 0 21.2 Example 4 1020.0 Example 5 25 22.4 Example 6 50 17.4 Example 7 75 20.5 Example 8 10016.2 Example 9 125 15.6 Example 10 250 9.3 Suture Transverse SutureTransverse Product Force (N/cm²) (Fmax N) Prolene Soft ™ Mesh 0 28.4Mersilene ™ Mesh 0 11.7 Example 3 0 21.4 Example 4 10 20.8 Example 5 2518.8 Example 6 50 20.2 Example 7 75 20.0 Example 8 100 20.3 Example 9125 17.3 Example 10 250 12.0

The stiffness of the materials described in Examples 3-10, Prolene Soft™mesh, and Mersilene™ Mesh was measured according to ASTM D4032-94Stiffness of Fabric by the Circular Bend Procedure. Test specimensmeasuring 102.0 mm wide and 204.0 mm long were loaded into a Zwicktensile test machine with a grip to grip separation of 1.0 mm and a testspeed of 300 mm/min. The test measures the force required to move aspecimen through a circular area. It should be noted that stiffermaterials may cause more irritation to surrounding tissues. Thestiffness values of the condensed surgical mesh were equivalent to theuncondensed with increase in the condensation force applied per unitarea up to 125 N/cm². The sample with a condensation force of 250 N/cm²showed an increase in stiffness. Stiffness Product Force (N/cm²)Stiffness (Fmax N) Prolene Soft ™ Mesh 0 3.13 Mersilene ™ Mesh 0 0.55Example 3 0 2.35 Example 4 10 1.90 Example 5 25 2.35 Example 6 50 2.16Example 7 75 2.03 Example 8 100 2.37 Example 9 125 2.34 Example 10 2502.98

The tensile strength of the materials described in Examples 3-10,Prolene Soft™ mesh, and Mersilene™ Mesh was measured according to ASTMD882-02 Standard Test Method for Tensile Properties of Thin PlasticSheeting. Test specimens measuring 10.0 mm wide and 100.0 mm long wereloaded into a Zwick tensile test machine with a grip to grip separationof 50.0 mm and a test speed of 500 mm/min. Materials were tested in themachine and transverse directions. Tensile strength provides ameasurement of the force required to rupture the surgical mesh implantsunder tension. The tensile strength was maintained with an increase inthe condensation force applied per unit area up to 75 N/cm². The sampleswith a condensation force of 100 and 125 N/cm² showed a moderatedecrease in tensile strength and the samples with a condensation forceof 250 N/cm² showed a more significant decrease. Tensile Machine ProductForce (N/cm²) Tensile Machine (N/cm) Prolene Soft ™ Mesh 0 27.75Mersilene ™ Mesh 0 27.16 Example 3 0 21.76 Example 4 10 21.70 Example 525 23.14 Example 6 50 21.46 Example 7 75 24.37 Example 8 100 21.20Example 9 125 19.94 Example 10 250 15.31 Tensile Transverse TensileTransverse Product Force (N/cm²) (N/cm) Prolene Soft ™ Mesh 0 20.97Mersilene ™ Mesh 0 15.04 Example 3 0 17.37 Example 4 10 16.69 Example 525 17.55 Example 6 50 18.02 Example 7 75 16.29 Example 8 100 16.41Example 9 125 15.40 Example 10 250 12.39

Example 11

We constructed a knitted polypropylene surgical mesh implant using 4 milmonofilament polypropylene fibre. The fibre was produced using MarlexHGX-030-01 polypropylene homopolymer. A warp knit was employed to givethe mesh exceptional tensile strength and to prevent runs andunravelling. A suitable mesh is produced when employing the followingpattern wheel or chain drum arrangements: front guide bar,1-0/1-2/2-3/2-1 and back guide bar, 2-3/2-1/1-0/1-2. The knittedsurgical mesh had elasticity in the machine and transverse directions.The elasticity, however, was not uniform in the machine and transversedirections. The elasticity was higher in the transverse directioncompared to the machine direction. To compensate for this difference, asample measuring 33 cm in the machine direction and 45 cm in thetransverse direction was stretched to 48 cm in the transverse directionwhile being held at 33 cm in the machine direction. The surgical meshimplant, while being held under tension, was condensation treated. Thesurgical mesh implant was brought to 155° C. under 75 N/cm² with vacuumbetween two layers of Kapton 2 mil polyimide film using a Lauffer RLKV40/1 vacuum lamination press. The difference in elasticity between thetransverse and machine directions was reduced.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.

1. A soft tissue implant comprising a condensed surgical mesh, the meshcomprising one or more biocompatible fibres, at least one of the fibrescomprising a monofilament fibre.
 2. An implant as claimed in claim 1wherein each fibre in the mesh comprises a monofilament fibre.
 3. Animplant as claimed in claim 1 wherein along at least part of at leastone fibre, the fibre is condensed.
 4. An implant as claimed in claim 3wherein the mesh has a void space between adjacent fibres in the mesh,and along the condensed part of the fibre, the mesh void space isreduced.
 5. An implant as claimed in claim 3 wherein along the condensedpart of the fibre: $\frac{A_{v}}{A_{F}} \leq 1.5$ where: A_(V)=area ofthe void between adjacent fibres in the mesh available for tissueinfiltration. A_(F)=cross-sectional area of the fibre.
 6. An implant asclaimed in claim 3 wherein along the condensed part of the fibre, thesurface area of the fibre available for contact with tissue is reduced.7. An implant as claimed in claim 6 wherein along the condensed part ofthe fibre: $\frac{P_{FC}}{P_{F}} \leq 0.8$ where: P_(FC)=Perimeter ofthe fibre, at a cross-section of the fibre, which is available forcontact with tissue. P_(F)=Total perimeter of the fibre, at across-section of the fibre.
 8. An implant as claimed in claim 1 whereinthe fibres are condensed at at least some points of intersection betweenthe fibres.
 9. An implant as claimed in claim 1 wherein the fibres areat least partially flattened at at least some points of intersectionbetween the fibres.
 10. An implant as claimed in claim 1 wherein themesh has at least one overlap region, at which at least one fibreoverlaps at least one other fibre, at least one of the fibres beingcondensed at the overlap region.
 11. An implant as claimed in claim 10wherein at the overlap region, one fibre is fused with an overlappingfibre.
 12. An implant as claimed in claim 10 wherein at the overlapregion, one fibre engages with an overlapping fibre.
 13. An implant asclaimed in claim 12 wherein the engagement of one fibre with anoverlapping fibre substantially prevents in-growth of tissue between theoverlapping fibres.
 14. An implant as claimed in claim 10 wherein theoverlapping fibres are condensed together.
 15. An implant as claimed inclaim 1 wherein the fibre comprises a polymer and/or a copolymer.
 16. Animplant as claimed in claim 1 wherein the fibre comprises polypropylene.17. An implant as claimed in claim 1 wherein the mesh is condensedsubstantially uniformly.
 18. An implant as claimed in claim 1 whereinthe mesh comprises a condensed region and an uncondensed region.
 19. Animplant as claimed in claim 1 wherein the mesh comprises at least tworegions which are differentially condensed.
 20. An implant as claimed inclaim 1 wherein the implant is configured for attachment to tissue. 21.An implant as claimed in claim 20 wherein the implant is configured tofacilitate coupling of an attachment element to the mesh.
 22. An implantas claimed in claim 21 wherein the attachment point comprises anattachment opening in the mesh to receive an attachment element, such asa suture, and/or a staple, and/or an adhesive.
 23. An implant as claimedin claim 20 wherein the mesh comprises one or more engagement formationsfor attachment of the mesh to tissue.
 24. An implant as claimed in claim23 wherein the mesh comprises a plurality of protrusions configured in awave-like or dimple like pattern.
 25. An implant as claimed in claim 1wherein at least part of the mesh is treated to increase the coefficientof friction of the mesh.
 26. An implant as claimed in claim 1 whereinthe mesh is configured to maintain the position of the mesh relative totissue.
 27. An implant as claimed in claim 26 wherein the mesh comprisesone or more engagement formations for engaging tissue.
 28. An implant asclaimed in claim 1 wherein at least a portion of the mesh is of acomposite configuration.
 29. An implant as claimed in claim 18 whereinthe implant comprises an inelastic element to reinforce the mesh.
 30. Animplant as claimed in claim 29 wherein the inelastic element is woveninto the mesh.
 31. An implant as claimed in claim 29 wherein theinelastic element is attached to a surface of the mesh.
 32. An implantas claimed in claim 1 wherein the thickness of at least part of the meshis in the range of from 0.001 inches to 0.04 inches.
 33. An implant asclaimed in claim 1 wherein the thickness of the mesh is substantiallyconstant across the mesh.
 34. An implant as claimed in claim 1 whereinthe thickness of the mesh varies across the mesh.
 35. An implant asclaimed in claim 1 wherein the density of at least part of the mesh isgreater than 0.081 g/cm³.
 36. An implant as claimed in claims 1 whereinthe density of the mesh is substantially constant across the mesh. 37.An implant as claimed in claim 1 wherein the density of the mesh variesacross the mesh.
 38. An implant as claimed in claim 1 wherein the meshpore size is uniform across the mesh.
 39. An implant as claimed in claim1 wherein the mesh pore size varies across the mesh.
 40. An implant asclaimed in claim 1 wherein the implant comprises a three dimensionalstructure.
 41. An implant as claimed in claim 1 wherein at least some ofthe mechanical properties of the mesh are substantially omnidirectional.42. A method of forming a surgical mesh, comprising one or morebiocompatible fibres, at least one of the fibres comprising amonofilament fibre, the method comprising the step of condensing atleast part of the mesh.
 43. A method as claimed in claim 42 wherein eachfibre in the mesh comprises a monofilament fibre.
 44. A method asclaimed in claim 42 wherein the mesh is condensed by applying heat to atleast part of the mesh.
 45. A method as claimed in claim 42 wherein themesh is condensed by applying pressure to at least part of the mesh. 46.A method as claimed in claims 42 wherein the mesh is condensed byapplying a vacuum to at least part of the mesh.
 47. A method as claimedin claim 42 wherein the method comprises the step of heat-setting themesh.
 48. A method as claimed in claim 42 wherein the method comprisesthe step of controlling the texture of the mesh.
 49. A method as claimedin claim 48 wherein the texture is controlled by arranging the mesh incontact with a control surface before the step of condensing isperformed.
 50. A method as claimed in claim 49 wherein the methodcomprises the step of maintaining the temperature of the control surfacesubstantially stable.
 51. A method as claimed in claim 49 wherein themethod comprises the step of maintaining the pressure of the controlsurface substantially stable.
 52. A method as claimed in claim 42wherein the method comprises the step of forming the mesh into athree-dimensional structure.
 53. A method as claimed in claim 42 whereinthe method comprises the step of treating the mesh to make at least someof the mechanical properties of the mesh substantially omnidirectional.54. A method of making a soft tissue implant, the method comprising: (c)providing a surgical mesh; and (d) condensing the surgical mesh togenerate-material useful as a soft tissue implant
 55. The method ofclaim 54, further comprising altering the size or shape of the materialto generate the soft tissue implant.
 56. The method of claim 54, whereinproviding the surgical mesh comprises extruding a biocompatible polymeror copolymer into a fibre and forming the surgical mesh from the fibre.57. The method of claim 56 wherein the biocompatible polymer orcopolymer is a non-absorbable polymer or copolymer.
 58. The method ofclaim 57 wherein the non-absorbable polymer is a polymer ofpolypropylene, polyethylene, polyethylene terephthalate,polytetrafluoroethylene, polyaryletherketone, nylon, fluorinatedethylene propylene, polybutester, or silicone, or a copolymer thereof.59. The method of claim 58, wherein the biocompatible polymer orcopolymer is an absorbable polymer.
 60. The method of claim 59, whereinthe absorbable polymer is a polymer of polyglycolic acid (PGA),polylactic acid (PLA), polycaprolactone, polydioxanone orpolyhydroxyalkanoate, or a copolymer thereof.
 61. The method of claim60, wherein the biocompatible polymer is collagen or a copolymercomprising collagen.
 62. The method of claim 57, wherein forming thesurgical mesh comprises knitting the fibre.
 63. The method of claim 54wherein the mesh comprises pores of a substantially uniform size. 64.The method of claim 54 wherein the mesh comprises pores that are greaterthan 50 micrometers in diameter.
 65. The method of claim 54 whereincondensing the surgical mesh comprises applying pressure and,optionally, heat to the mesh.
 66. The method of claim 65 wherein thepressure or heat is applied for a time and under conditions sufficientto reduce the void space within the mesh.
 67. The method of claim 65wherein the pressure or heat is applied for a time and under conditionssufficient to reduce the surface area available for contact with apatient's tissue.
 68. The method of claim 66, wherein the pressure orheat is applied to the mesh uniformly.
 69. The method of claim 66wherein the pressure or heat is applied to the mesh non-uniformly. 70.The method of claim 65 wherein the pressure or heat is applied to themesh while the mesh is under vacuum.
 71. The method of claim 54 furthercomprising inserting, into the material, an opening for receiving anattachment element.
 72. The method of claim 54 wherein the material isabout 0.001-0.040 inches thick.
 73. The method of claim 54 wherein thematerial is of a size and shape appropriate for stabilizing orsupporting the bladder neck, urethra, pelvic floor, or abdominal wall.74. The method of claim 54 further comprising fashioning the materialinto a tubular or conical shape.
 75. A soft tissue implant made by themethod of claim
 54. 76. A method of making a soft tissue implant, themethod comprising: (d) providing a surgical mesh; (e) condensing thesurgical mesh by applying pressure and, optionally, heat to the mesh,wherein the pressure and, optionally, the heat, is applied for a timeand under conditions sufficient to reduce the void space within themesh; and (f) cleaning or sterilizing the mesh, thereby generatingmaterial useful as a soft tissue implant.
 77. A soft tissue implantcomprising a woven or knit monofilament mesh having a density greaterthan 0.081 g/cm³, the space between the monofilament mesh constitutingpores of about 500 μm to about 10 mm in diameter.